This disclosure relates to crimping sleeves. More particularly, it relates to a crimping sleeve for use in small enclosures such as used in a medical or commercial application. Referring to FIG. 1, an existing enclosure or tube has a small envelope E within it in which the crimp sleeve at joint J must be used to join wire W to fiber F. The small envelope must accommodate both the crimp sleeve length (about 0.300 inches crimped) and the crimp sleeve travel (about 0.560 inches) based on pull wire travel along a longitudinal direction.
There is a need for a crimping sleeve which can join PTFE (Polytetrafluoroethylene) coated stainless steel wire to a fiber formed of Vectran braid. Vectran is a very fine weave of Liquid Crystal Polymer. The crimped sleeve must be configured to fit within a relatively small area within the enclosure and must be about to hold about 94% of the tensile strength of the wire.
Given the low coefficient of friction of PTFE coatings relative to commonly used ductile crimp materials such as copper and aluminum, there is a need for a crimp sleeve material which has a high coefficient of friction to PTFE and still remains ductile. Ductility is a critical feature of the sleeve material. There is also a need to provide crimp sleeve material which has a high coefficient of friction since the gripping surface area of the sleeve is limited by usable space in the enclosure. It is also important to use a high coefficient of friction material because methods of squeezing a highly ductile material such as copper to a greater degree only extrudes material outside the usable space of the enclosure. Titanium is such a material which has a high coefficient of friction and is less ductile than copper but more ductile than aluminum.
A disadvantage of squeezing less ductile materials such as aluminum to impart more normal force in the crimp is that the plastic braid or the wire can be damaged or brutalized thereby compromising the strength of the crimp assembly. Thus, there is need to control the compression to impart the necessary force to hold the wire and the braid in the crimp, keep the crimp within the space allowed by the device, and yet not brutalize or damage the braid or the wire with the crimp. This is accomplished by tightly controlling compression with die press tooling and tight tolerancing on the sleeve.
Still other benefits and aspects of the disclosure will become apparent upon a reading and understanding of the following detailed description.